In underground drilling, such as gas, oil, or geothermal drilling, a bore is drilled through a formation deep in the earth. Such bores are formed by connecting a drill bit to sections of long pipe, referred to as a drill pipe, that are connected so as to form an assembly commonly referred to as a drill string. The drill string may extend from above the surface of the earth to the bottom of the bore. A drill platform or drill rig is a structure used to house machinery for drilling.
Often, a drilling system utilizes a top drive motor to drill wells. Top drive motors are mounted in the drilling mast of the drilling rig and typically raised and lowered in the mast by a rail system. The top drive motors may be a power, electrical, or hydraulic motor, for example, and may provide a motive force to rotate the drill string. The distal end of the drill string may be referred to as the bottom hole assembly or downhole assembly. The downhole assembly may include a drill bit that advances to form a bore in the surrounding formation.
A portion of the downhole assembly may incorporate an electronic system with sensing modules for taking measurements downhole. For example, measurements with respect to the drill bit may help the operator direct the drill bit properly. The sensing modules in the bottom hole assembly may transmit the collected information to the surface such that they may be analyzed by a drill operator for controlling the drilling process. Information may be transmitted to the surface via pressure pulses in drilling fluid, for example, or the sensors may be analyzed once they are pulled up out of the downhole assembly during a break in the drilling operation. The operator may use the information related to the downhole operations to modify the drilling operation, such as to control the direction in which the drill bit advances in a steerable drill string, for example.